It has been suggested that at least some of the decline in performance of elderly persons on psychological tasks may result from the protracted persistence of stimuli in the nervous system. In this view there is a resulting "smearing" of temporally contiguous stimuli which limits significantly their processing as discrete sensory events. The goals of this ongoing research program are to evaluate in vision the utility of the stimulus-persistence hypothesis, to identify the locus of any noted persistence effects, to examine such persistence in terms of other extant theoretical conceptualizations and to determine if possible the mechanisms which underly any age-related increase in the persistence of visual stimuli. The results of the studies completed thus far indicate that: 1) the period over which form stimuli can be integrated is elevated in old age, 2) there is an age deficit in the detection of stimulus offset asynchrony which is consistent with an increase with age in the duration of a "free-running" perceptual moment, and 3) there does not seem to be an age difference in the minimum duration of a visual event indicating that it is unlikely that a change in this duration can be used to explain an age-related increase in visual persistence. Research is currently in progress to: 1) determine the extent of age differences of temporal integration in color vision, 2) estimate the extent of peripheral (prechiasmal) and central (retrochiasmal) contributions to form and color integration by comparing the effects on age differences of using monoptic and dichoptic presentations of form and color stimuli, and 3) determine if the age decrement in temporal resolving power can be accounted for by an hypothesis of differential aging of the "transient" versus "sustained" channels of the visual system.